Potent and Specific Antibacterial Activity against Escherichia coli O157:H7 and Methicillin Resistant Staphylococcus aureus (MRSA) of G17 and G19 Peptides Encapsulated into Poly-Lactic-Co-Glycolic Acid (PLGA) Nanoparticles
Grupo de Investigación en Bioquímica y Microbiología (GIBIM), Universidad Industrial de Santander, Bucaramanga 680002, Colombia
Escuela de Microbiología, Facultad de Salud, Universidad Industrial de Santander, Bucaramanga 680002, Colombia
Departamento de Química, Universidad Nacional de Colombia, Bogotá 111321, Colombia
Departamento de Ciencias Básicas, Facultad de Salud, Universidad Industrial de Santander, Bucaramanga 680002, Colombia
Author to whom correspondence should be addressed.
Antibiotics 2020, 9(7), 384; https://doi.org/10.3390/antibiotics9070384
Received: 22 May 2020 / Revised: 27 June 2020 / Accepted: 1 July 2020 / Published: 7 July 2020
(This article belongs to the Special Issue Synthesis and Pharmacokinetics of Antibiotics)
Antimicrobial peptides constitute an excellent alternative against conventional antibiotics because of their potent antimicrobial spectrum, unspecific action mechanism and low capacity to produce antibiotic resistance. However, a potential use of these biological molecules as therapeutic agents is threatened by their low stability and susceptibility to proteases. In order to overcome these limitations, encapsulation in biocompatible polymers as poly-lactic-glycolic-acid (PLGA) is a promising alternative for increasing their stability and bioavailability. In this work, the effect of new synthetic antimicrobial peptides GIBIM-P5S9K (G17) and GAM019 (G19) encapsulated on PLGA and acting against methicillin resistant Staphylococus aureus (MRSA) and Escherichia coli O157:H7 was studied. PLGA encapsulation allowed us to load around 7 µg AMPs/mg PLGA with an efficiency of 90.5%, capsule sizes around 290 nm and positive charges. Encapsulation improved antimicrobial activity, decreasing MIC50 from 1.5 to 0.2 (G17NP) and 0.7 (G19NP) µM against MRSA, and from 12.5 to 3.13 µM for E. coli O157:H7. Peptide loaded nanoparticles could be a bacteriostatic drug with potential application to treat these bacterial E. coli O157:H7 and MRSA infections, with a slow and gradual release.